Isolating relay board circuit and isolating relay card

Abstract

The utility model discloses an isolation relay board circuit and isolation relay card spare, isolation relay board circuit includes: power input module, terminal input module, isolation relay module and DI output module, and power input module provides power supply for entire isolation relay board circuit, and indicates power access state with power supply indication unit, and terminal input module is used to receive the DI switching quantity signal of field equipment sending, isolation relay module is used for isolating DI switching quantity signal, and the circuit protection module among isolation relay module is used for protecting device not to be damaged, and red green double light indicating lamp module is used for indicating whether signal input, whether insurance is intact, DI output module is used for outputting the DI switching quantity signal after isolation to the DI receiving module of DCS system. The utility model can solve the technical problem of poor signal adaptability of existing isolation relay board, inconvenient troubleshooting, and high cost of wiring.

Description

Technical Field

[0001] The present application relates to the technical field of DCS design, and in particular relates to an isolated relay board circuit and an isolated relay card. Background Art

[0002] In the field of industrial automation control, a Distributed Control System (DCS) is a core architecture that ensures the continuity, safety and control accuracy of production in process industries such as chemical engineering and energy. Among them, the transmission of DI digital switch signals between on-site equipment (such as sensors and actuators) and the DCS system requires electrical isolation implemented by an isolation component, so as to prevent on-site electrical interference from intruding into the DCS system and avoid control deviations or equipment damage. Especially in the chemical industry, there are many production process links, complex working conditions, and diverse on-site signal types (including passive dry contacts, active wet contacts, etc.), and the requirements for signal isolation reliability and fault response speed are much higher than those in other industries. Therefore, as a bridge for signal transmission, the performance of the isolated relay board directly determines the overall operation stability of the DCS system.

[0003] At present, although the isolated relay boards matched with mainstream DCS systems can realize the basic signal isolation function, they are difficult to adapt to the special requirements of the chemical industry and have significant technical pain points. Existing solutions lack flexibility in signal compatibility: usually, the processing modes for dry contact signals and wet contact signals cannot be switched through simple operations, and it is necessary to design separate circuits or replace modules for different signal types, which increases the system configuration cost and debugging difficulty. More critically, the existing solutions have serious insufficient indication for key fault states: after the one-time fuse in the circuit protection module is blown, maintenance personnel need to check one by one to locate the faulty channel, and there is no clear indication when the positive and negative poles of the power supply are reversed, which results in long time consumption and low efficiency in fault troubleshooting, and easily delays production recovery. Utility Model Content

[0004] In view of this, the present utility model provides an isolated relay board circuit and an isolated relay card, which can solve the technical problems of poor signal adaptability, inconvenient fault troubleshooting, and high cost caused by excessive wiring of existing isolated relay boards.

[0005] In a first aspect, an embodiment of the present utility model provides an isolated relay board circuit, comprising: a power input module, a terminal input module, an isolated relay module and a DI output module, wherein the power input module provides 24VDC power for the entire isolated relay board circuit, and the isolated relay module comprises a circuit protection module and an indicator light module; The terminal input module is used to receive DI switch signals sent by field devices. The DI switch signals include passive dry contact signals and active wet contact signals. The terminal input module can switch between dry contact mode and wet contact mode to adapt to the DI switch signals. One end of the isolation relay module is connected to the terminal input module, and the other end is connected to the DI output module. This isolation module isolates the DI switch signal from the signal output by the DI output module to the downstream DCS system to avoid electrical interference. The circuit protection module protects the relay and other electronic components from high-voltage damage by activating its own fuse when the external input voltage exceeds the load of the relay coil in the isolation relay module. The indicator light module indicates the input status of the DI switch signal and the integrity status of the fuse in the circuit protection module. The DI output module is equipped with a standard DB37 interface, which is used to output the DI switch signal isolated by the isolation relay module to the DI receiving module of the DCS system through the standard DB37 interface. The power input module integrates a power indicator unit to indicate the connection status of the 24VDC power supply.

[0006] Optionally, the indicator light module integrated in the isolation relay module is a red-green dual-lamp integrated structure. The green lamp in the red-green dual-lamp integrated structure is used to indicate whether the terminal input module receives the DI switch signal. The green lamp is on when the DI switch signal is input and off when the DI switch signal is not input. The red lamp in the red-green dual-lamp integrated structure is used to indicate the integrity status of the fuse in the circuit protection module. The red lamp is on when the fuse is intact and off when the fuse blows.

[0007] Optionally, the circuit protection module integrated in the isolation relay module has a one-time pluggable replaceable fuse; the one-time pluggable replaceable fuse blows when the external input voltage exceeds the relay coil load.

[0008] Optionally, the terminal input module switches between the dry contact mode and the wet contact mode through two sets of jumpers; the two sets of jumpers correspond to the circuit adaptation logic of the passive dry contact signal and the active wet contact signal, respectively.

[0009] Optionally, the power input module is a dual-redundant 24VDC power input structure. The dual 24VDC power supplies in the dual-redundant 24VDC power input structure are each equipped with an independent power indicator unit. The connection status of each 24VDC power supply is individually indicated by the red and green dual lights of the corresponding power indicator unit, which makes it easy to distinguish the working status of the two redundant power supplies.

[0010] Optionally, the power indicator unit is a dual red and green light. When the positive and negative terminals of the 24VDC power supply are correctly connected, the green light in the power indicator unit is on; when the positive and negative terminals of the 24VDC power supply are reversed, the red light in the power indicator unit is on.

[0011] Optionally, the power supply range of the power input module is adaptively adjusted according to the signal mode of the terminal input module. When the terminal input module switches to the dry contact mode, the power input module simultaneously supplies power to the relay coil of the isolation relay module and the indicator light module; when the terminal input module switches to the wet contact mode, the power input module only supplies power to the relay contact side of the isolation relay module.

[0012] Optionally, the relay in the isolation relay module is a mechanical relay with a 24V coil, and the mechanical relay can be detachably inserted into a dedicated relay base.

[0013] Optionally, multiple isolation relay modules are provided, and the front-end coil of each isolation relay module is connected to the DI switch signal output terminal of a field device one by one; the positive terminals of the rear-end contacts of the multiple isolation relay modules are all connected to the 24V positive terminal of the power input module, and the negative terminals of the rear-end contacts are collected and connected to the standard DB37 interface of the DI output module to realize the independent isolation and centralized output of multiple DI switch signals.

[0014] Secondly, this utility model provides an isolation relay card, which includes the isolation relay circuit described in the first aspect.

[0015] The isolation relay board circuit and isolation relay card provided in this embodiment of the invention provide 24VDC power through a power input module and integrate a power indicator unit, which can clearly indicate the power connection status, solving the problem of unclear power connection status in existing solutions (such as difficulty in detecting reversed positive and negative terminals); the terminal input module supports switching between dry contact mode and wet contact mode, which can flexibly adapt to both passive dry contact and active wet contact DI switch signals of field equipment, solving the problems of poor signal adaptability and the need for frequent module replacement or design of dedicated circuits in existing solutions; the isolation relay module realizes the isolation between field DI switch signals and back-end DCS system signals, which can effectively avoid electrical... Interference is minimized, ensuring reliable signal transmission. The integrated circuit protection module of the isolation relay module can protect the device by triggering a fuse when the external voltage exceeds the relay coil load, solving the problems of insufficient effective high-voltage protection and easily damaged components in existing solutions. The integrated indicator module can also intuitively indicate the signal input status and fuse integrity, solving the problem of inconvenient troubleshooting of faults (such as fuse blowout or no signal input) in existing solutions. Furthermore, with the standard DB37 interface of the DI output module, it can easily connect to the DI receiver module of the DCS system, comprehensively improving the circuit's adaptability to complex working conditions in industries such as chemical engineering, reducing the difficulty of fault diagnosis and the risk of device damage, and ensuring the stable operation of the DCS system.

[0016] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more obvious and understandable, specific embodiments of this utility model are given below. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 The circuit topology diagram of an isolation relay board circuit provided by an embodiment of the present invention is shown; In the picture: 1-Power input module; 2-Terminal Input Module; 3-Isolation relay module, 31-Circuit protection module, 32-Indicator light module; 4-DI output module; 5 - Two sets of jumpers. Detailed Implementation

[0018] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0022] The following is combined Figure 1 This invention describes the circuit of an isolation relay board according to some embodiments of the present invention.

[0023] like Figure 1As shown, the isolation relay board circuit includes: a power input module 1, a terminal input module 2, an isolation relay module 3, and a DI output module 4. The power input module 1 provides 24VDC power to the entire isolation relay board circuit. The isolation relay module 3 includes a circuit protection module 31 and an indicator light module 32. The terminal input module 2 is used to receive DI switch signals sent by field devices. The DI switch signals include passive dry contact signals and active wet contact signals, and the terminal input module 2 can switch between dry contact mode and wet contact mode to adapt to the DI switch signals. One end of the isolation relay module 3 is connected to the terminal input module 2, and the other end of the isolation relay module 3 is connected to the DI output module 4, used to transmit the DI switch signals to the terminal input module 2. The DI output module 4 isolates the signal output to the back-end DCS system to avoid electrical interference. The circuit protection module 31 protects the relay and other electronic components from high voltage damage by its own fuse action when the external input voltage exceeds the load of the relay coil in the isolation relay module 3. The indicator module 32 indicates the input status of the DI switch signal and the integrity status of the fuse in the circuit protection module 31. The DI output module 4 is equipped with a standard DB37 interface to output the DI switch signal isolated by the isolation relay module 3 to the DI receiving module of the DCS system through the standard DB37 interface. The power input module 1 integrates a power indicator unit to indicate the connection status of the 24VDC power supply.

[0024] Among them, the mode switching function of terminal input module 2 can solve the problem that existing solutions require separate circuit design or module replacement for dry / wet contact signals, greatly improving the adaptability to diverse DI signals in the chemical industry and reducing system configuration costs; the power indicator unit of power input module 1 and the indicator light module 32 of isolation relay module 3 can form dual status feedback. The former can quickly identify wiring errors such as reversed positive and negative terminals of the power supply, while the latter can intuitively determine whether the DI signal is input and whether the fuse is intact, which can solve the pain points of existing solutions where fuse blowouts are difficult to detect and faults need to be checked one by one, thus improving on-site operation and maintenance efficiency; the signal isolation function of isolation relay module 3 is combined with the high-voltage protection function of circuit protection module 31, which not only avoids the impact of on-site electrical interference on the DCS system, but also protects core components (such as relays) from damage when the voltage is abnormal, reducing the frequency of component replacement and maintenance costs; in addition, the standard DB37 interface of DI output module 4 meets the industrial standardization docking requirements, which can reduce the connection complexity with the DCS system DI receiving module, and improve the overall reliability, adaptability and operation and maintenance convenience of the circuit under complex chemical working conditions, meeting the strict requirements of DCS system for signal isolation transmission.

[0025] Specifically, the indicator light module 32 integrated in the isolation relay module 3 is a red-green dual-lamp integrated structure. The green light in the red-green dual-lamp integrated structure is used to indicate whether the terminal input module 2 has received a DI switch signal. The green light is on when there is a DI switch signal input and off when there is no DI switch signal input. The red light in the red-green dual-lamp integrated structure is used to indicate the good condition of the fuse in the circuit protection module 31. The red light is on when the fuse is good and off when the fuse blows.

[0026] The indicator module 32, with its integrated red and green dual-lamp structure, precisely addresses the core issues of inconvenient fault diagnosis and insufficient status indication of protection devices in existing isolation relay boards. Specifically, it addresses the pain point of requiring channel-by-channel inspection for fuse blowouts in existing solutions. The red light directly reflects the fuse's integrity status through its "on / off" indicator, eliminating the need for on-site personnel to disassemble circuits or use testing tools. Simply observing the red light going out allows for rapid identification of the blown fuse channel, significantly reducing troubleshooting time. The green light provides a unified indication of the DI switch signal input status (regardless of dry or wet contact mode), resolving the difficulty in determining signal presence or absence. This is particularly useful in complex operating conditions with multiple channels and signal types in the chemical industry, quickly distinguishing between no signal input and device malfunction (e.g., green light off + red light on → no signal, green light off + red light off → fuse blown), preventing misjudgments. Furthermore, the dual lights are integrated within the isolation relay module 3, eliminating the need for additional wiring or indicator units. This simplifies circuit layout, reduces hardware costs, improves on-site maintenance efficiency, and meets the rapid fault response requirements of chemical DCS systems.

[0027] The circuit protection module 31 integrated in the isolation relay module 3 uses a one-time replaceable fuse. This one-time replaceable fuse blows when the external input voltage exceeds the load of the relay coil. When the external input voltage connected to the field equipment exceeds the rated load of the relay coil in the isolation relay module 3, the one-time replaceable fuse will blow immediately, cutting off the transmission path of the excessively high voltage and preventing high voltage from directly impacting the relay coil and other electronic components in the circuit.

[0028] One-time pluggable replaceable fuses only blow when the voltage exceeds the relay coil load. This avoids circuit interruptions caused by accidental triggering under normal voltage and quickly cuts off the circuit under abnormal high voltage, effectively protecting core components such as relay coils and indicator lights from burnout. This reduces hardware damage costs and improves circuit reliability. The pluggable design of the one-time pluggable replaceable fuse greatly simplifies the maintenance process. No soldering or disassembly of the circuit board is required; replacement can be completed simply by manually plugging and unplugging the fuse. It is particularly suitable for the needs of DCS systems in industries such as chemical engineering for rapid maintenance without downtime, reducing production downtime caused by maintenance and improving overall operation and maintenance efficiency.

[0029] like Figure 1As shown, the terminal input module 2 switches between dry contact mode and wet contact mode via two sets of jumpers 5. The two sets of jumpers 5 correspond to the circuit adaptation logic for passive dry contact signals and active wet contact signals, respectively. The two sets of jumpers 5 correspond to the circuit path design for passive dry contact signals and active wet contact signals, respectively. For passive dry contact signals that do not require their own power supply, one set of jumpers 21 can switch the circuit to a path that requires external power from the power input module 1 (meeting the requirement of external power supply for dry contact signal transmission). For active wet contact signals that have their own power supply, the other set of jumpers 21 can switch the circuit to a path that does not require additional power supply and directly transmits the signal (avoiding conflict between active signals and external power). On-site operators only need to plug, unplug, or adjust the physical state of the two sets of jumpers 5 to complete the signal mode switching without disassembling the circuit or replacing the terminal input module 2 itself.

[0030] Addressing the pain point of existing solutions requiring separate circuit design or module replacement for active and passive signals, this utility model provides two sets of jumpers that can flexibly switch modes without replacing terminal input module 2 or reconfiguring the circuit. This adapts to complex scenarios in the chemical industry where signals include both active and passive elements with no specific patterns, significantly improving signal adaptation flexibility and reducing system configuration costs. Furthermore, the two sets of jumpers achieve mode switching by adjusting the internal connection logic of the circuit, reducing the number of external wiring connections and lowering on-site electrical installation workload and wiring costs. The jumper switching operation is intuitive and simple; operators only need to adjust the jumper positions according to the on-site signal type, without requiring professional programming or complex debugging, shortening signal access debugging time and further enhancing the practicality and engineering adaptability of the entire isolation relay board circuit.

[0031] In specific application scenarios, the power input module 1 is a dual-redundant 24VDC power input structure. The dual 24VDC power supplies in the dual-redundant 24VDC power input structure are each equipped with an independent power indicator unit. The connection status of each 24VDC power supply is indicated separately by the red and green dual lights of the corresponding power indicator unit, which makes it easy to distinguish the working status of the two redundant power supplies.

[0032] The power indicator unit configured in the power input module 1 is a dual red and green light. When the positive and negative terminals of the 24VDC power supply are connected correctly, the green light in the power indicator unit will light up; when the positive and negative terminals of the 24VDC power supply are reversed, the red light in the power indicator unit will light up.

[0033] The dual-redundancy design of power input module 1 avoids the risk of a single power supply failure causing the entire circuit to shut down in existing solutions. Chemical industry DCS systems have extremely high requirements for signal transmission continuity. This design ensures continuous circuit operation through the other power supply even when one power supply is disconnected or abnormal, reducing production control signal interruptions caused by power problems and improving overall system reliability. Furthermore, independent red and green dual-indicator lights address the pain point of existing solutions where reversed power connections or single-channel faults are difficult to detect. Field personnel can quickly determine which power supply is reversed or has no input simply by observing the light status of the two indicator units, without needing to use multimeters or other specialized tools, significantly shortening power fault location time.

[0034] In specific application scenarios, the power input module 1 serves as the core power supply for the isolation relay board circuit. Its power supply range is not fixed. The power supply range of the power input module 1 can be adaptively adjusted according to the signal mode of the terminal input module 2. When the terminal input module 2 switches to dry contact mode, the power input module 1 simultaneously supplies power to the relay coil of the isolation relay module 3 and the indicator light module 32. When the terminal input module 2 switches to wet contact mode, the power input module 1 only supplies power to the relay contact side of the isolation relay module.

[0035] Existing solutions, if they do not differentiate between signal types and fix the power supply, may result in problems such as the coil not being powered in dry contact mode, leading to signal insufficiency, or the dual power supply in wet contact mode burning out the relay coil. This design, however, uses adaptive adjustment to ensure that the power supply in different modes perfectly matches the signal characteristics, which can significantly reduce the probability of device damage and improve circuit reliability. In addition, operators do not need to manually adjust the power supply wiring or configuration of the power input module after switching signal modes; they only need to switch the terminal module mode to achieve automatic power supply logic adaptation, which can adapt to the multi-signal type and rapid deployment conditions in the chemical industry.

[0036] In specific application scenarios, the relay in isolation relay module 3 is a 24V coil mechanical relay, which can be detachably inserted into a dedicated relay base. This design allows for easy replacement of the mechanical relay, enabling on-site personnel to complete maintenance within minutes without the need for specialized soldering tools, significantly shortening troubleshooting time. It is suitable for the maintenance needs of DCS systems in the chemical industry, minimizing downtime.

[0037] In specific application scenarios, multiple isolation relay modules 3 are set in the same isolation relay board circuit. The front-end coil of each isolation relay module 3 is connected to the DI switch signal output terminal of a field device. The positive terminals of the rear-end contacts of multiple isolation relay modules 3 are all connected to the 24V positive terminal of the power input module 1, and the negative terminals of the rear-end contacts are collected and connected to the standard DB37 interface of the DI output module 4 to achieve independent isolation and centralized output of multiple DI switch signals. This design reduces the number of power supply cables and output cables by connecting the positive terminals of the rear-end contacts to the power supply and the negative terminals to the DB37 interface, which significantly reduces the workload of electrical assembly and hardware costs.

[0038] The application principle of this utility model is as follows: In the distributed control system (DCS) of industries such as chemical industry, a dual redundant 24VDC power supply is first connected through the power input module. Its integrated red and green dual light indicator unit can provide real-time feedback on whether the positive and negative terminals of the power supply are correctly connected, ensuring the stability of the power supply foundation; then, the DI switch signals (passive dry contact or active wet contact) sent by the field equipment are connected through the terminal input module. The operator switches the terminal input module to the corresponding mode through two sets of jumpers according to the signal type, so that the power input module can adaptively adjust the power supply range according to the mode. In dry contact mode, the relay coil and indicator light module of the isolation relay module are powered, while in wet contact mode, only the relay contact side is powered. Each signal corresponds to an independent isolation relay module. The module electrically isolates the field-side DI switch signals from the back-end DCS system signals to avoid interference. At the same time, its integrated circuit protection module (including a one-time pluggable fuse) blows the fuse when the external voltage exceeds the relay coil load, protecting the device from damage. The integrated red and green dual indicator light module indicates whether the signal has been input by turning on or off the green light and whether the fuse is intact by turning on or off the red light. Finally, the multi-channel isolated DI signals are aggregated at the negative terminal of the back-end contacts and transmitted centrally to the DI receiving module of the DCS system through the standard DB37 interface of the DI output module, realizing reliable, monitorable, and easy-to-maintain isolated transmission between the field signals and the DCS system.

[0039] Based on the above, Figure 1 The isolation relay board circuit shown in the figure, correspondingly, this embodiment also provides an isolation relay card, which includes the above-described isolation relay board circuit. Figure 1 The diagram shows an isolation relay circuit. Since isolation relay circuits with one or more channels require terminal blocks, a power input module, and a DB37 connector, to save costs, a single isolation relay card in chemical projects typically has 16 to 32 channels. 32 terminals of the DB37 connector connect to the positive terminals of the 16-32 channel isolation relay circuit outputs, 2-4 terminals are the negative common terminal, and 1-2 terminals can be connected to the card's ground.

[0040] In the exemplary embodiments of this application, any of the aforementioned embodiments of the isolation relay circuit are applicable to the isolation relay card, and will not be described in detail here.

[0041] The isolation relay board circuit and isolation relay card provided by this utility model have the following beneficial effects: 1. Improved system reliability: When a high voltage surge occurs in a certain channel, the protection circuit can protect other devices. When a 220VAC high voltage is connected, only the devices in the channel connected to the high voltage may be burned out, and other channels will not be damaged through the common terminal.

[0042] 2. Added indicators for one-time fuse status and reversed power cord connection, enabling on-site engineers to detect faults in a timely manner.

[0043] 3. The component positions are carefully optimized for easy replacement of jumpers or one-time fuses by engineers.

[0044] 4. High anti-interference performance: The high-standard design ensures that the EMC (electromagnetic compatibility) anti-interference performance meets the level 3 requirements.

[0045] It is understood that the circuit structure shown in the figure does not constitute a limitation on a specific circuit, and may include more or fewer circuit components than shown, or combine certain circuit components, or deploy different circuit components.

[0046] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An isolated relay board circuit, comprising: include: The circuit includes a power input module, a terminal input module, an isolation relay module, and a DI output module. The power input module provides 24VDC power to the entire isolation relay board circuit. The isolation relay module includes a circuit protection module and an indicator light module. The terminal input module is used to receive DI switch signals sent by field devices. The DI switch signals include passive dry contact signals and active wet contact signals. The terminal input module can switch between dry contact mode and wet contact mode to adapt to the DI switch signals. One end of the isolation relay module is connected to the terminal input module, and the other end is connected to the DI output module. This isolation module isolates the DI switch signal from the signal output by the DI output module to the downstream DCS system to avoid electrical interference. The circuit protection module protects the relay and other electronic components from high-voltage damage by activating its own fuse when the external input voltage exceeds the load of the relay coil in the isolation relay module. The indicator light module indicates the input status of the DI switch signal and the integrity status of the fuse in the circuit protection module. The DI output module is equipped with a standard DB37 interface, which is used to output the DI switch signal isolated by the isolation relay module to the DI receiving module of the DCS system through the standard DB37 interface. The power input module integrates a power indicator unit to indicate the connection status of the 24VDC power supply.

2. The isolated relay board circuit of claim 1, wherein, The indicator light module integrated in the isolation relay module is a red-green dual-lamp integrated structure. The green lamp in the red-green dual-lamp integrated structure is used to indicate whether the terminal input module has received the DI switch signal. The green lamp is on when the DI switch signal is input and off when the DI switch signal is not input. The red lamp in the red-green dual-lamp integrated structure is used to indicate the integrity status of the fuse in the circuit protection module. The red lamp is on when the fuse is intact and off when the fuse blows.

3. The isolated relay board circuit of claim 1, wherein, The circuit protection module integrated in the isolation relay module has a one-time replaceable fuse; the one-time replaceable fuse blows when the external input voltage exceeds the relay coil load.

4. The isolated relay board circuit of claim 1, wherein, The terminal input module switches between the dry contact mode and the wet contact mode through two sets of jumpers; the two sets of jumpers correspond to the circuit adaptation logic of the passive dry contact signal and the active wet contact signal, respectively.

5. The isolated relay board circuit of claim 1, wherein, The power input module is a dual-redundant 24VDC power input structure. The dual 24VDC power supplies in the dual-redundant 24VDC power input structure are each equipped with an independent power indicator unit. The connection status of each 24VDC power supply is indicated separately by the red and green dual lights of the corresponding power indicator unit, which makes it easy to distinguish the working status of the two redundant power supplies.

6. The isolated relay board circuit of claim 5, wherein, The power indicator unit has two lights, red and green. When the positive and negative terminals of the 24VDC power supply are connected correctly, the green light in the power indicator unit will light up; when the positive and negative terminals of the 24VDC power supply are reversed, the red light in the power indicator unit will light up.

7. The isolated relay board circuit of claim 1, wherein, The power supply range of the power input module is adaptively adjusted according to the signal mode of the terminal input module. When the terminal input module switches to the dry contact mode, the power input module simultaneously supplies power to the relay coil of the isolation relay module and the indicator light module. When the terminal input module switches to the wet contact mode, the power input module only supplies power to the relay contact side of the isolation relay module.

8. The isolated relay board circuit of claim 1, wherein, The relay in the isolation relay module is a mechanical relay with a 24V coil, and the mechanical relay can be detachably inserted into a dedicated relay base.

9. The isolated relay board circuit of claim 1, wherein, The isolation relay module is provided in multiple ways. The front-end coil of each isolation relay module is connected to the DI switch signal output terminal of a field device. The positive terminals of the rear-end contacts of the multiple isolation relay modules are connected to the 24V positive terminal of the power input module. The negative terminals of the rear-end contacts are collected and connected to the standard DB37 interface of the DI output module to realize the independent isolation and centralized output of multiple DI switch signals.

10. An isolated relay card, comprising: The isolation relay card includes the isolation relay circuit as described in any one of claims 1-9.

Images